TRRL recently tested a single-span half-scale model of a bridge deck constructed of four steel i-beams acting compositely with a reinforced concrete slab. The design conformed to the bridge design Code, BS 5400, and contained no arbitrary reserves of strength. The deck was loaded first to the Highways HA + HB design ultimate condition and then the HB load was increased until a partial collapse was achieved. A sudden flexural failure of a parapet edge beam occurred. This paper compares the experimental results with non-linear finite element calculation obtained using a TRRL finite element program. Results of analyses carried out by three organisations under contract to TRRL are also given. (A)